Needle-thread-controlling mechanism for sewing-machines



A. H. DE VOE.

NEEDLE THREAD CONTROLLING MECHANISM FOR SEWING MACHINES.

APPLICATION FILED MAY II, I 9I8- 1. Mm 2 I I h P III I Y T III I I II 9 H W III I; Q E 2 W T R 2 z fi T m m I W m A .III. III I w M Y t ll 1 HA u f B A. H. DE VOE.

NEEDLE THREAD CONTROLLING MECHANISM FOR SEWING MACHINES. APPLICATION FILED MAYII, 1918.

1,366,364. Patented Jan. 25, 1921.

2 SHEETSSHEET 2- WIT/VESSfS INVENTORI A TTORNEY ALBERT H. DE VOE, OF WESTFIELD, NEW JERSEY,

ASSIGNOR TO THE SINGER MANU- FACTURING COMPANY, .A. CORPORATION OF NEW JERSEY.

NEEDLE-THREAD-CONTROLLING MECHANISM FOR SEWING-MACHINES.

Application filed May 11,

To all whom it may concern.

Be it known that I, ALBERT H. DE Von, a citizen of the United States, residing at Westfield, in the county of Union and. State of New Jersey, have lnvented certain new and useful Improvements in Needle-Thread- Controlling Mechanisms for Sewing- Machines, of which the following is a specification, reference being -had therein to the accompanying drawings. I

-This invention relates to a chain-stitch sewing machine and particularly to mechanism for controlling the needle-thread thereof.

In the manufacture of gloves it is customary to stitch ornamental seams convergently disposed fanwise on the back thereof to impart to the article whenfinished a smart appearance which catches the purchasers eye. A variety of seams have previously been employed for this purpose but they have required more or less special stitchforming mechanism. It is an object ofkthe present invention to form an ornamental appearin seam with a standardized type of stitchorming mechanism whose thread control permits of concatenating the thread in a uniform manner and drawing the thread up withenoughtension to enchain the loops snug but not tight and Without wrinkling the material between successive needle-punctures therein.

The invention consists essentially of nipping and pulling devices which are mounted on the overhanging arm and actuated from the main-shaft below the work-support in such relative sequence that the pulling device acts to draw up a slight amount of slack thread between the needle and the sup ly before the nipping device grips the t read, afterwhich the pulling device draws from the supply enough thread, but no more, than is required in the next stitch to be formed.-

It is preferably applied to a four-needle four-looper type of single-thread chainstitch machine making four independent seamsin close and parallel rows and the thread may be of a color contrasting harmoniously with the material of the glove.

The invention in one of its forms is illustrated in the accompanying drawings in which Figure 1 is a rear elevation of a ma chine equipped therewith. Fig. 2 is a front elevation of the needle-bar, a portion of the throat-plate and loopers appearing. Fig. 3

Specification of Letters Patent.

Patented Jan. 25, 1921. 1918. Serial No. 234,009.

is an end elevation partly in section of the mechan sm actuating the nipping and pulling dBVI QG S. 1g. 4 is a plan View of the same. 1 1g. 5 1s a perspective view on an enlarged scale showing the character of the stitch formed and Fig. 6 is a perspective view of the nipping and pulling devices on tog of the overhanging arm.

he machine illustrated is of .the singlethread chainstitch type employing four needles 1 secured in a needle-clamp 2 of any suitable construction, the one shown being of the same construction as that disclosed in my copending application Serial No. 234,007 hled May 11, 1918, and also employing four loopers 3 operated in any suitable manner from the main-shaft 4 which is located beneath the work-support 5 through slots in which feed-dogs 6 advance the work in a manner Well known.

The needle-clamp 2 is secured to the lower end of a needle-bar 7 reciprocated by a link 8 connected to one end of a needle-lever 9 fulcrumed at 10 to the overhanging arm 11 and joined by a ball-and-socket connection 12 to a pitman 13' which is actuated from an eccentric 14 on the main-shaft 4:.

The foregoing construction is old and Well known to those skilled in the art. What is now to be described pertains particularly to the new and novel thread control of the present invention.

Mounted on the needle-bar 7 is a pluralapertured thread-guide 15 of angular form which is adjustably secured by the screwand-slot connection 16 within a groove 17 lformed in the collar 18 fast on the needle- Mounted on top of the overhanging arm 11 between the needle-bar and constant tensions 19, which may be of any suitable form and are of a number preferably corresponding to the number of needles, is a nipper which consists of a sheet-metal base 21 supporting at one end a spring 22 whose opposite end is free to move up and down in proximity to a plurality of eyes 23 formed in the upright lip 24 atthe end of the sheetmetal base. base 21 and passing loosely through the spring 22 is a screw 25, which a clamp-nut 26 serves to hold in an adjusted position, the head of the screw 25 limiting the upward movement or flexure of the spring 22. The sheet-metal base 21 may be secured to the Threaded into the sheet-metal the spring 22 as will presently overhanging arm by the screw 27, Figs. 3 and 6, or in any other suitable manner. The spring 22 preferably has a wing 27' formed at the front edge thereof to prevent accidental displacement of the needle-threads which are adapted to pass over the spring as indicated by the dot-and-dash lines in Fig. 1'. An arm or finger 28 extending at substantially right angles from the'rod 29, as best shown in Fig. 3, is moved during the operation of the machine into engagement with appear, the spring-bein free to grip a the threads against the nger.

Mounted also on top of the overhanging arm between the constant tensions 19 and nipper is a thread-puller which consists of fixed thread-restraining members or uides 3132 of angular 'form in spaced re ation on opposite sides of-a movable thread-engaging arm or finger 33 extending at substantially right angles from a rod 34, similar to the nipper finger and rod 2829. One of the fixed thread-restraining devices, 31, is provided with aU-shaped incision as shown and the other, 32, with a plurality of apertures 35'. Both of.the fixed thread-restra1n-- ing devices are secured to the overhanging arm by screws 35.

The rods 29 and 34 are passed throu h apertures 3738, respectively, adjacent e mpper and thread-puller which are on top of the overhangingarm and at their lower ends these rods are suitably ivoted to crank-arms 39-40 on a rock-sha t 41 which is parallel to the main-shaft 4 and is actuated from an eccentric 42 thereon embraced by a strap 43 that slidably receives a pin44 fastened by the set-screw 45 to one end. of the rock-shaft.

The crank-arms 39-40 are so disposed and proportioned as to impart movements of different lengths and velocity to the bent ends or fingers 2833 of the rods 2934, respectively. movement of the fingers 2833 enables the nipper to grip the thread from about the time the looper-sheds the previous needleloop on the descent of the needle until after the needle-eye in its succeeding ascent reaches the upper surface of the work. This timing of the contact'and engagement of finger or thread-puller 28 with the spring 22, and of course the consequent grip of the needle-threads passing between them, en-

ables the thread-puller or finger 33 to perform a dual function during its down stroke.

It first takes up some of the slack in the needle-thread while the needle descends to loop-entering position and then, after the thread is gripped, it draws off from the sup-- ply through the constant tensions 19 that amount of thread which is required to form the next stitch.

In consequence of the action on the thread The resulting differential- '1. In a chain-stitch sewing machine stitch- 80 forming mechanism including a needle-bar and a needle carried thereby, a work-feeding mechanism in combination with needles thread controlling mechanism comprising an eye carried by the needle-baiadjacent its upper end, a' constant tension between the needles and the supply, an intermittent tension between the eye carried by the needlebar and the constant tension, and a combined take-up and pull-off 'means between the intermittent and constant tensions said intermittent tension being adapted to grip the thread about the time the looper sheds its loop and to maintain its hold on the thread until the eye of the needle reaches the workin its ascent, and said combined take-up and pull-off means being adapted to first draw thread from the portion'thereof leading to the needle and subsequently to draw thread from the supply.

2. In a chain-stitch sewing machine in combination, stitch-forming mechanism including a needle and a looper in combination with needle-thread controlling mechanism including intermittent and constant tensions and an intermediate thread-puller, said intermittent tension being actuated to grip the thread between the beginning and ending of the movement of the thread-puller whereby the latter function's first as a takeup and then as a pull-off on the descent of the needle."

3. In a single thread chain-stitch sewing machine, in combination, stitch-forming mechanism including a needle, work-feeding mechanism, means for controlling the thread including intermittent and constant tensions and also including a thread-puller located between said tensions, and means for relatively actuating said intermittent tension and said pull-01f causing the latter to first draw upon the slack-thread between needle and the nipper during the descent rial between the successive needle punctures of strain without leaving the successively enchained loops free to stand away from the Work.

4. In a single-thread chain-stitch machine, in combination, stitch-forming mechanism including an eye-pointed needle, work-feeding mechanism, and thread controlling mechanism including a take-up eye fixed to the needle-bar, a nipper, a thread-puller, means for actuating said nipper and thread-puller to draw slack from the needle until it enters a loop of needle-thread on the looper and to draw thread from the supply which latter is not available until after the eye of the needle reaches the work in its ascent.

5. In a single-thread chain-stitch sewing machine, in combination, stitch-forming mechanism including an eye-pointed needle, work feeding mechanism, an eye carried by the needle-bar, a nipper, a thread-puller on the supply side of the nipper, a constant tension on the supply side of the thread puller, said nipper being actuated to grip the thread between the beginning and ending of the drawing action of the threadpuller to allowthe latter to draw up some of the slack thread between the needle and nipper during a portion of the descent of the needle and to draw thread from the supply during the remainder of the needles descent.

6. In a single-thread chain-stitch sewing machine, in combination, stitch-forming mechanism including a needle, work-feeding mechanism, a take-up eye on the needle-bar, a nipper, a thread-puller on the supply side of the nipper, a constant tension on the supply side of the thread-puller means for actuating the thread-puller to draw some of the slack thread between the needle and nipper during the descent of the needle and until it has entered the needle-loop on the looper, means for actuating the nipper to grip the thread when the needle has entered the needle-loop on the looper, and for maintaining the nippers grip on the thread until the eye of the needle is above the work in its ascent.

7. In a sewing machine having an overhanging arm and stitch-forming mechanism including a needle, a main-shaft, a rockshaft driven therefrom, a nipper, a threadpuller, connections between the rock-shaft and both the nipper and thread-puller, said connections being constructed and arranged to time the nippers grip between the beginn1ng and endlng of the descent of the thread-puller.

, 8. In a single-thread chain-stitch machine, in combination, an overhanging arm, stitchforming mechanism including a needle, a

nipper for gripping the needle-thread, a thread-puller having fixed and movable members, a main-shaft, a rocking member driven therefrom, and connectionsbetween the movable member of the thread-puller and the nipper for gripping the needlethread between the beginning and ending of the drawing action of the pull-01f to cause the latter to first take thread from the needles side thereof and to subsequently take thread from the supply side thereof, said means holding the needle-thread gripped by the nipper until the eye of the needle reaches the work in its ascent.

9. In a sewing machine having stitchforming mechanism including a needle, a main-shaft, a rock-shaft driven therefrom, a plurality of arms on said rock-shaft, reciprocatory members connected to said plurality of arms, a nipper interposed in the path of one of said reciprocatory members, thread confining means located adjacent the other of said reciprocatory members, and means confining the reciprocatory members to movement in a prescribed path.

10. In a sewing machine having stitchforming mechanism includin a needle, a cloth-plate, an arm overhanglng the clothplate, a main shaft located below the'clothplate, a rock-shaft, a pair of arms of different lengths on said rock-shaft, a nipper supported by the overhanging arm, thread restraining means on the overhanging arm between the nipper and the supply, fingers adjacent the nipper and thread restraining means, said fingers being confined adjacent said overhanging arm and being also connectedIto the arms of the rock-shaft.

11. forming mechanism and work-feeding mechanism, in combination, a cloth-plate, an arm overhanging the cloth-plate, a main-shaft located below the cloth-plate,-a rock-shaft, an eccentric on the main-shaft, a strap embracing said eccentric and having a pin and socket connection with the rock-shaft whereby the rock-shaft is oscillated, a plurality of arms of different lengths on said rock-shaft, a nipper, a constant tension device on said overhanging arm, spaced thread guides intermediate said nipper and constant tension, and means moving between said spaced thread-guides and also down upon said nipper for pulling off and ripping respectively the needle-thread, said means being connected to said arms on the rock-shaft.

In testimony whereof, I have signed my name to this specification.

ALBERT H. DE VOE.

n a sewing machine having stitch-- 

